However, creating your own WAD file from a disc you legally own, for the purpose of system backup or modding, falls into a legal gray area (protected under "fair use" for archival in some jurisdictions, but actively contested by Nintendo's EULA).
Move the ISO to your PC. Use a tool like Wii Backup Fusion to extract the "Partition 1" (the game's data partition) into a folder. You are looking for the DATA folder, which contains filesys and main.dol . Super Mario Galaxy 2 Wad File
Just remember the golden rules of the modding community: However, creating your own WAD file from a